diff options
Diffstat (limited to 'src/network/kernel')
| -rw-r--r-- | src/network/kernel/qnetworkinformation.cpp | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/network/kernel/qnetworkinformation.cpp b/src/network/kernel/qnetworkinformation.cpp index a156dd08ece..66be77c383a 100644 --- a/src/network/kernel/qnetworkinformation.cpp +++ b/src/network/kernel/qnetworkinformation.cpp @@ -440,6 +440,36 @@ QNetworkInformationBackendFactory::~QNetworkInformationBackendFactory() object will also be destroyed in this thread, and various backend-specific components may rely on being destroyed in the same thread as it is created. + One possible use case for QNetworkInformation is to monitor network + connectivity status. reachability() provides an indication of whether the + system is considered online, based on information reported by the + underlying operating system or plugin. However, this information may not + always be accurate. For example, on Windows, the online check may rely on + connectivity to a Microsoft-owned server; if that server is unreachable + (e.g., due to firewall rules), the system may incorrectly report that it is + offline. As such, reachability() should not be used as a definitive + pre-check before attempting a network connection, but rather as a general + signal of connectivity state. + + To use reachability() effectively, the application must also understand + what kind of destination it is trying to reach. For example, if the target + is a local IP address, then Reachability::Local or Reachability::Site may + be sufficient. If the destination is on the public internet, then + Reachability::Online is required. Without this context, interpretring the + reported reachability may lead to incorrect assumptions about actual + network access. + + \warning Only Linux and Windows provide support for the finer-grained + Reachability::Site and Reachability::Local options. On Android and Apple + platforms reachability() is limited to reporting only Online, Offline or + Unknown. Therefore, any logic that relies on detecting Local or Site level + connectivity must include appropriate platform checks or fallbacks. + + \snippet code/src_network_kernel_qnetworkinformation_reachability.cpp 0 + \dots + \snippet code/src_network_kernel_qnetworkinformation_reachability.cpp 1 + \dots + \sa QNetworkInformation::Feature */ @@ -612,6 +642,14 @@ QNetworkInformation::TransportMedium QNetworkInformation::transportMedium() cons application should perform certain network requests or uploads. For instance, you may not want to upload logs or diagnostics while this property is \c true. + + \snippet code/src_network_kernel_qnetworkinformation_metering.cpp 0 + \dots + \snippet code/src_network_kernel_qnetworkinformation_metering.cpp 1 + \dots + \snippet code/src_network_kernel_qnetworkinformation_metering.cpp 2 + \dots + \snippet code/src_network_kernel_qnetworkinformation_metering.cpp 3 */ bool QNetworkInformation::isMetered() const { |